Parallel jaw pliers



Fb.22, 1949. AJJMUTER I 2,462,536

PARALLEL JAW PLIERS Filed Feb. 2, 1945 3 Sheets-Sheet 1 Feb. 22, 1949. A. J. MUTER I ARALLEL JAW PLIERS J 3 Sheets-Sheet 2 Filed Feb. 2, 1945 Feb. 22, 1949. J, MUTER 24 621536 PARALLEL JAW PLIERS Filed Feb. 2, 1945 s Sheets-Sheet s i; U E 20 Patented Feb. 22, 1949 PARALLEL JAW PLIERS Arthur John Muter, London, England Application February 2, 1945, Serial No. 575,823 In Great Britain November 2, 1943 2 Claims.

This invention has reference to improvements in and relating to parallel jaw devices of the kind in which a pair of jaws are constructed and arranged to open and close in sliding rectilinear fashion, as distinct from pivotally swinging through an angle, in order to perform their gripping, crushing, cutting, perforating or other function. Parallel jaw devices of this kind are applicable to pliers, tattooing forceps, castrators, vices and the like.

The primary object of the invention is to provide a sturdy structure in which the jaws are mutually supported and guided during operation. A further object is to provide such a structure which lends itself to easy incorporation with a pair of handles particularly in a manner for producing a pronounced mechanical advantage whereby a comparatively light effort on the handles will result in a good working pressure between the jaws.

With these and other objects in view themvention consists of a pair of jaws having slidably interfitted base members, each base including a tongue projecting towards its adjacent base and a complemental channel in which the opposing tongue slidably fits. The jaws are preferably substantially L-shape for the purpose of the invention, the uprights of the L being, or carrying, the jaws, and the bottoms constituting the aforesaid base members, the channel running partly along the same immediately under the upright, the bottom then being reduced in thickness both ways (height and transversely) to terminate in the tongue. Means may be incorporated to prevent separation of the interfitting base members in the transverse direction.

In order that the said invention may be readily understood reference is directed to the following description of some embodiments of the invention, given by way of example, which are illustrated by the accompanying drawings, wherein:

Figure l is a front elevation of a pair of tattooing or perforating forceps suchas might be used. for instance, in puncturing identification marks on the ears of cattle;

Figure 2 is a side view thereof;

Figure 3 is a front elevation of a pair of jaws detached from the forceps seen in Figures 1 and 2, and without the facing devices on the jaws;

Figure 4 is a perspective view of the jaw members seen in Figure 3 but completely separated one from the other, and

Figure 5 is a front elevation of a pair of pliers constructed according to the invention.

In both the illustrated examples, and with particular reference to Figure 4, the essential feature is a pair of jaws l and 2 of substantially L- shape, the uprights of which carry the actual jaws 3 and 4 respectively, and the bottoms 5 constitutinga pair of slidably interfitted base members. Each base member 5 is formed with a channel 6 running partly along the same immediately under the upright of the L, and is then reduced in thickness both as regards height at and transverse dimension 3 to terminate in a tongue I. The tongues l are complemental to their respective grooves 6 in that each is an easy sliding fit in the groove of the other base member to which it is opposed. Thus when fitted together the jaws are mutually supported by this double interfitment, each receiving slidably a part of the other. They may be adjusted to any width between the jaws 3 and 4 within the limits of the tool, the overlapping bi-tongued support resulting in a simple and sturdy structure, very rigid in use.

Dealing particularly with Figures 1 and 2 the application of the invention previously described in the schedule of figures, shows the attachment of a suitable form of operating handles, and a specific jaw-facing device.

Firstly in this embodiment, one jaw 3 is furnished with a pair of cheeks 8 fixedly attached, and adapted to receive a plurality of interchangea-ble perforating stamps 9 each having pins arranged in the form of a requisite letter, numeral or design. These stamps 9 slide in the cheeks 8 by meansof a dovetail interconnection, those in the upper cheek sliding vertically, and those in the lower cheek horizontally. They are held in position by the D-headed screws Ill. The other jaw 4 is provided with a soft platen H (such as of rubber or other soft and resilient material) stretched thereover and clamped by plates [2 on the back of the jaw. A resilient buffer plate i3 is interposed between the jaws to constitute an ejector plate for forcing the ear off the perforating stamps. The force exerted by this buffer plate may be regulated by the milled nut M.

So as to obviate looseness and relative movement of the jaws in-the transverse direction longitudinal grooves 24 are formed along the upper edges of the tongues 1 and these are engaged by balls or rollers 25 housed in recesses in the top wall of the channels 6. The balls 25 may be replaced by any suitable projection, and the arrangement may be reversed, viz: projection on the tongue and groove along the channel wall. Also, the

elesed together bringing the jaws l groove and projection intereng'ag'enint may be along the lower edges of tongue and channel.

The handles and their linkage to the jaws are designed to give an easy action and a mechanical advantage in securing, by leverage, a sufl'icient pressure between the jaws with a minimum of effort when gripping and closing the handles. The'two handles i5 are pivoted together by the lugs H5, at pivot pin l1. They each form a, two armed lever with short arms ill (the other arm's being the long arms or handles H5). The short arms are pivoted respectively to a pair of intermediate links l9, these latter being themselves" pivoted together at 20, and comprising counterparts on each side of the jaw bases 5; The pivb'ts 2B are free and independent of the jaws I and 2. These intermediate links i9 are each'in'the form of a two-armed lever, one arm being pivoted tothe handles at H, and the other to the jaws at" 22, preferably at a point located above the channels 6. There are two-pairs of intermediate links f9: one pair on each side of the jaws.

Thus by closing together the handles l5, the pivots 2 are splayed apart, and the pivots 22 and 2 together. The-jaws are preferably maintained normally in the-open position by the spring 23. The opening "movement of the jaws is limited in any suitable way such as by the abutting of the short arms l8' ef thehandles.

Referring to Figure 5', the construction and action o'f th'e jaws land 2 and of the handles 65 and associated members are similar to those particular features in the preceding description, and as the saine'reference numerals have been applied to the same or corresponding, parts as in Figures 1-% the construction and operation will be sufliciently understood. In this case, however, the invention is applied to a pair of cutting pliers and the shape of the jaws l and 2 are altered accordingly; The actual gripping heads 26 of the jaws have the conventional pointed shape, and also the serrated faces 27 of most general purpose pliers, whilst the inside upper edges of one side pair of the intermediate links Illa are formed as cutting edges 28 and made to meet when the faces z'l'come together.

The foregoing is an example of one compound form of handle, but other forms such as a simple cross-pivoted pair of handles, the short arms l8 acting oppositely to the forms illustrated with the pivots 2| direct on the respective jaws. may be adopted.

. I claim: U

1. A tool having a, pair of oppositely dispdsed L-shaped gripping jaws having relatively slidable interfitting base portions, a pair of handles pivoted together, a pair of short arms extending from each handle beyond the pivotal point of said handles, links intermediately pivoted together each having one end pivoted to one of said short arms and the other end to one of the jaws above its base portion, and means between said interfitting base portions adapted toprevent transverse separation of said slidable interfitting ba'se portions when the jaws are spread apart substantially in parallelism prior to gripping the work 7 2. Parallel jaw tools comprising in combinanona* pair of handles pivoted together, each handle being in the form of a two-armed lever with long arms and short arms, two pairs of intermediate links also pivoted together as two- 'armedl'eversemd which are pivoted at adjacent ends 0" the short arms of the" handws', L-sh'a'p'ed having uprights to the lo'wer end of whi'ch the other ends of the said links a repivoted, each hori'zontal'part of each'jaw having a channel and tongue which engage and receive complementary' parts on" the horizontal part of the other" jaw, interengaging means between said channels; and'torigues for preventing separation of the interengagingparts of thejaw's' inatran's verse direction, said tongues being provided with longitudinal grooves, and the means between the said channelsand tongues for preventingseparation of the interengaging parts of thQjaWS in a transverse; direction comprise members projectinginto the said grooves, N

ARTHUR. JOHN MUTER.

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